1. Field of the Invention
The subject matter disclosed herein relates to the detection and response of unwanted fueling of an internal combustion engine.
2. Discussion of the Prior Art
As used herein, the term “fugitive fueling” means a phenomenon in which an engine receives fuel in excess of that which a fuel controller intends to deliver, either by injectors or by another fuel delivery device. Fugitive fueling may occur in a variety of situations. For example, if an engine is operated in a hydrocarbon-contaminated atmosphere such as could occur in the event of a spill at a petroleum transfer terminal or a recycling facility, sufficient unwanted or fugitive hydrocarbons may be inducted by the air system of an engine to cause overspeed and severe engine damage. A mishap such as a vehicular accident or train wreck may create a fugitive fueling situation, too.
Another type of fugitive fueling occurs due to a leak in an engine lubrication system. Such a leak may occur in a turbocharger or other component connected with the engine's air inlet system. Those skilled in the art will appreciate that engines, particularly diesel engines, are capable of operating quite well on lubricating oil, including lubricating oil aspirated into the engine's cylinders as a result of leaking turbocharger seals, or failed turbocharger bearings, or as a result of damage inflicted by dropped poppet valves, or yet other sorts of internal leak paths which result in oil being inducted into the engine's air inlet system. Yet another type of fugitive fueling may occur if a fuel injector is severely impaired, so that the injector either flows more than it is directed to flow, or simply leaks.
A need exists for a system and method for detecting and responding to fugitive fueling prior to overspeeding, thereby allowing an engine to be stopped before uncontrolled operation occurs.